686273-52-9Relevant academic research and scientific papers
Synthesis of 3,4-disubstituted piperidines by carbonyl ene and prins cyclizations: Switching between kinetic and thermodynamic control with Bronsted and Lewis acid catalysts
Williams, Jodi T.,Bahia, Perdip S.,Kariuki, Benson M.,Spencer, Neil,Philp, Douglas,Snaith, John S.
, p. 2460 - 2471 (2007/10/03)
A novel approach to cis and trans 3,4-disubstituted piperidines is described. Carbonyl ene cyclization of aldehydes 4a-e catalyzed by MeAlCl 2 in refluxing chloroform afforded the trans piperidines 7a-e with diastereomeric ratios of up to 93:7,
Synthesis of 3,4-disubstituted piperidines by carbonyl Ene and Prins cyclizations: A switch in diastereoselectivity between Lewis and Bronsted acid catalysts
Williams, Jodi T.,Bahia, Perdip Singh,Snaith, John S.
, p. 3727 - 3730 (2007/10/03)
(graph presented) A novel diastereoselective approach to cis and trans 3,4-disubstituted piperidines is described. Carbonyl ene cyclization of aldehydes 6a-e catalyzed by the Lewis acid methyl aluminum dichloride in refluxing chloroform affords trans piperidines 8a-e with diastereomeric ratios of up to 93:7. By contrast, Prins cyclization of 6a-e catalyzed by hydrochloric acid at low temperatures affords cis products 7a-e with diastereomeric ratios of up to 98:2.
